It’s hard to get anywhere in explaining what time is without saying that it is secondary or subsequent to change, and there is a pretty broad agreement that this is the case. Both Plato and Aristotle agreed to it, and their disciples followed them. Mc Taggart defines the principle in question well in his famous essay The Unreality of Time:
It would, I suppose, be universally admitted that time involves change. A particular thing, indeed, may exist unchanged through any amount of time. But when we ask what we mean by saying that there were different moments of time, or a certain duration of time, through which the thing was the same, we find that we mean that it remained the same while other things were changing. A universe in which nothing whatever changed (including the thoughts of the conscious beings in it) would be a timeless universe.
The immediate retort, of course, is that we have no problem imagining a world of completely frozen motion and thought (it’s a common enough sci-fi or comic-hero superpower) and there is a clear sense in talking about how long such a thing would be frozen. And so as long as we are thinking about “A universe in which nothing whatever changed (including the thoughts of the conscious beings in it)”, why can’t we think of it existing for some time? Even if we leave aside the question of “how long”, isn’t it obvious that a frozen world is still a temporal one, simply because the presence or absence of motion isn’t usually thought to have any effect on whether something is temporal? The genius of McTaggart’s explanation is that he incorporates a response to this: ” A particular thing, indeed, may exist unchanged through any amount of time. But when we ask what we mean by saying that there were different moments of time, or a certain duration of time, through which the thing was the same, we find that we mean that it remained the same while other things were changing”. And so we can eliminate this or that change from the temporal world, but to think on the basis of this that we could make some sort of radical division between thought and change would be, in light of Mc Taggart’s principle, the fallacy of composition. Whatever might change or not in a particular case, it remains that the modality of time tracks perfectly the modality of change.
This is a particularly powerful example of a metaphysical principle, not because it is the clearest one, but because it shows the sort of discourse on experience that metaphysics requires. The principle is not revealed by the repetition of experience, but by the deepening meditation on what is given in initial experience. There is a good deal of discourse involved in getting the point of seeing the principle clearly, but the discourse does not consist in a multiplication of some one experience nor in the unification of some field of data under a single idea. There is only the development of what is given in an initial experience of temporality, which reveals the nexus between temporality and a change that differs from the change in time.